


The Seventh Impossible Thing

by IshtarsDream



Series: The Case of the Missing Wizard [3]
Category: Doctor Who, Harry Potter - J. K. Rowling, Sherlock (TV), Sherlock Holmes - Arthur Conan Doyle
Genre: Alternate Universe - Vampire, Fictons, Potterlock, Vampire Johnlock if you squint, Vampire Sherlock, Wholock
Language: English
Status: Completed
Published: 2015-07-23
Updated: 2015-07-23
Packaged: 2018-04-10 20:21:02
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 881
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4406207
Author URL: https://archiveofourown.org/users/IshtarsDream/pseuds/IshtarsDream
Summary: <blockquote class="userstuff">
              <p>Sherlock Holmes, vampire Detective, introduces John Watson to the most improbable man in the multiverse. The world ends (a bit).</p>
            </blockquote>





	The Seventh Impossible Thing

**Author's Note:**

> "They" say you can't have vampires and aliens in the same story. "They" are wrong.
> 
> This sprang full-blown into my head when I woke up this morning. No idea where it came from.

The vampire detective and his blogger stepped out onto the roof of St. Bart’s in the wee hours of the morning.

“Sherlock, you said we were going to meet someone. Who’d meet us here?”

“The most dangerous man you’ll ever know,” said Sherlock Holmes. “Don’t worry, you’ll like him.” He pulled an ornate silver brooch with a sapphire mounted in the centre out of his pocket and pressed his thumb on the stone as if it were a button. Then he tossed the brooch onto the rooftop about ten feet in front of them. A few moments later, a distinctive wheezing, groaning sound broke the pre-dawn silence, and a blue police box heaved itself into existence where the brooch had fallen.

“Oh, you have _got_ to be kidding me!” cried John. “This is impossible!”

“You’ve believed six impossible things before breakfast,” said the detective. “Including me. So why not a seventh?”

The door of the box opened and a tall, oddly-dressed man stepped out. “Sherlock? Is that you?”

“In the flesh.”

“You’ve changed.”

“So have you.” Sherlock smiled widely, something he didn’t do often because most people found the fangs upsetting, and embraced the other man like an old friend.

“So who’s this?”

“John, this is The Doctor. Doctor, John Watson.”

“You found another one?”

“Great-grandson of the original, actually.”

John, meanwhile, was giving The Doctor a close look and trying to peek into the open door of the box at the same time. “You don’t look at all like the one on the telly. He’s all hair and eyebrows.”

“That was a regeneration or two ago,” said The Doctor. “The telly people will catch up eventually. Oh, do go on and look inside, I can see you’re dying to,” he said, opening the door of the TARDIS wider.

While John indulged his curiosity, The Doctor pulled Sherlock aside for a quiet conversation. “So you and …?”

Sherlock shook his head. “No. I mean, I do and he might, but this …” He gestured at his own undead form. “I can’t ask him to. But I can’t stop myself. I gave him a Mark last night.” He shuddered, thinking of John lying passive and compliant beneath him, double puncture marks prominent on his neck. “If things keep on, I’ll kill him, Turn him, or make him into a Thrall, and I refuse to do any of those things. I’ll die the True Death first.”

“You recall the discussion we had when I first met you?”

“This reality is an unstable ficton bubble, held open by one determining factor. You didn’t say then, but that’s me, isn’t it?”

The Doctor nodded gravely. “You’ve already held it open far longer than I thought possible. You may have noticed things are fraying a bit around the edges.”

“All sorts of unpleasant things are creeping in,” Sherlock agreed. “Time I closed up shop, then. But what happens when I die for good?”

“This world collapses into a fluctuating quantum state until some new variant of the determining factor is imposed on it. Anything and anyone in it is destroyed and recreated in different versions without being aware of it.”

“And John – my John – would cease to exist along with everything else?”

“I’m afraid so, yes.”

“What if you take him out of it? Would he survive? Could you reinsert him into a different version of the world?”

“He’d stabilize outside the bubble, yes. I could give him a good run, then reinsert him and the new ficton would form around him. You’d be in it, but a different you, hopefully a happier one.”

“Would he remember – me?”

“As a passing dream. That’s all I can offer you.”

“It will have to be enough. I’ve already had an extra century, I can’t ask for more.”

The Doctor glanced at the open door of the TARDIS. John had disappeared inside, and his exclamations of wonder could be heard clearly. “Do you want to explain? Have a chance to say goodbye?”

“Just go ahead and kidnap him, he’s used to that. I’m afraid if I … I might change my mind.”

“All right then. Best not to draw this out.”

The two men embraced again, old friends who would never meet again.

The Doctor stepped into the TARDIS, closing the door behind him. “John, let me show you something!”

Wheezing and groaning sounded again, fading into silence.

On the roof of St. Bart’s, a vampire stood alone and waited for the dawn.

 

* * *

 

 

John came awake with a start and almost fell off the sofa in the sitting room of 221B.

Sherlock looked up from where he was working in the kitchen, making a fresh batch of mouseballs for Gwenhwyfar. The owl was perched on the back of John’s kitchen chair, “supervising”.

“Finally awake, are we? Maybe now you can turn off that DVD you were watching. The theme music is driving me mad.”

“You could have turned it off yourself, you know,” said John, getting up to stop the DVD’s endless cycling through the main screen.

“I didn’t want to disturb you. You were exhausted.”

“You should have. That damned music got into my head, too. You wouldn’t believe the dream I had.”

“Really? Try me,” said Sherlock with a smile. “These days, I can believe six impossible things before breakfast.”


End file.
